(engl.: fail-safing – to avoid (yokeru) inadvertent errors (poka)) is a behavior-shaping constraint, or a method of preventing errors by putting limits on how an operation can be performed in order to force the correct completion of the operation. The concept was originated by Shigeo Shingo as part of the Toyota Production System. One example is the inability to remove a car key from the ignition switch of an automobile if the automatic transmission is not first put in the “Park” position, so that the driver cannot leave the car in an unsafe parking condition where the wheels are not locked against movement.
Poka-yoke – Japanese term that means mistake proofing. A poka-yoke device is one that prevents incorrect parts from being made or assembled or easily identifies a flaw or error. Developed by a Japanese industrial engineer Shigeo Shingo